Sizing compositions and their preparation and use in paper



Patented July 8, 1952 SIZING: coMPosrrroNs AND THEIR PREP- 1 TI N ND SE A K j Harco Jacob Tadema,'Amsterdam; Netherlands,

I assignor to Shell" Development Company; San Francisco, Calif.,:a corporation of Delaware No Drawing. Application July 28,1943, Serial j No 'lfi lfirll ln the Netherlands Aprill4,.1943

' section -lfilublic Law 690, August 8,1946-- 1 ,1; x 1'. ,Patent'expires Aprill i, 1963 aims invention sates-lathe swinger-fibrous. materials, such-gas ,-paper,, cardboard, text le;

threads or fabrics, imitation leather, and the like. It deals. with improved sizing compositions which may be applied during or aftermanufacture of articles of such types It also deals;- with anew method. ofbproducing; sizing compositions and with improved .articlesdof :manufacture which have been sized or "made" waterrrepellen't withrthe. new compositions of the invention. I.

A wide variety of compositions have been used; for the sizing'of .fibrousmaterials' ofdifierent types. Rosin or'colophony, for .exampleyiscommonly employed for paper sizingbut man'yother resins-waxes, bituminous. or' asphaltic materials, tars,- etc. have been-proposedfor such use. The usual practice is tozapply an aqueoussolution or suspension .offthe sizirigagentato thefibers. to be sized-and precipitate the size-in the fibers by:

addition of asuitable precipitant. Thus, inthc manufacture of paper or :cardboard, suspensions-v ofcolophony saponified-with alkali hydroxides or carbonates are added to the fibers in the beater or Holland machine and. precipitated with paper maker's alumor the like.

It has now beenrfound that more advantageous sizingv compositions comprise aqueous emulsions containing. -controlled proportions of colophony with the predominantly cyclic extracts obtainable rom m n al-1.01 artie ilar1 p t m. s- FOr best-resultsitis desirable not only toregulate.

the proportion of colophony to I cyclic extract in I the mixture but alsoto control the character of the .emulsion, particularly with respect to fine ness ofthe dispersion. L 4 Accordingto ;the invention, improved; sizing compositions are produced by. emulsifying together with water? to about 30 parts byweightof, coloph'o ny; withl'95 to 70 parts by weight .of. the chosen cyclicextract, preferably 10 to tainable by} extracting petroleum or related oils, including hydrogenation products of coal and the like, with solvents, which are selective for nonparaffinic constituents. 'A wide variety of polar solventsmay be used for the preparation of such extracts, liquid .sulfurdioxide, phenol, cresylic acid, furfural, beta,betadichlorethyl ether, nitrobenzene the sulfolanes and sulfolenes, and the like beingtypical examples of suitable solvents.

U. S. Patents Nos-2,023,375, 2,357,344, 2,360,859

and 2,365,898, rob instance, describesolvents which rnay beadvantageously used. Combinationsof solvents, as phenol with cresylic acid, or liquid sulfur dioxide with benzene ortoluene, for instance, are useful and the use of the so-called double, solvent process employing mutually im miscible solvents e. g. cresylic acidwith propane, also gives suitable extracts. Methods of this type which may be used are described, for examplein U. S. Patents ,Nos. 2,029,190, 2,124,602 j and 2,322,083. There are also advantages in'reexj tracting the initial extract ,with an immiscible. solvent to improve the selectivity of the extraction. Thus, extraction of Edeleanu extracts of-lubrieating oils with gasoline or the like has been found to improve the vsizing properties of the compositions producedqtherefrom in accordance with the invention.- Other extraction methods which may be .used are described, for, example, in II. S. Patents Nos. 2,081,721, 2,114,524, and 2,139,392. Extractive distillation may be 'used'in place of or in combination with the previously mentioned extraction methods, suitable processes being described, for-example, in U. S. Patents Nos. 2,109,157 and 2,407,820.

Extracts of heavier petroleum oils such as the lubricating oils and residual stocks are especially usefulin thenew sizing compositions of the inpart'sof Icolophony wi h 90 to 80 partsof the ex;

tractfpreierably using an; aqueoussolutionof a b 'se havingfa concentration of 5% towabo ut 30% base by weight and: containing, fromapfimXi",

mately' halfp toabout double the amount of base required for [complete saponification of the, solo; phony used. If proportions of colophony to aromatic extract outside-the foregoing limits are used, difilculties 'jare, encountered. in producing,

dispersions pfthe desired uniformity andjstability.

there is a marked: drop in'the sizing quality; oijthe, product.

l'Thecyclicextracts used in thenew compositionsflof the invention arethe products of predominantly aromatic and naphthenic nature obvention, but other fractions of petroleum or re';

lated hydrocarbon products can also be used successfully as sources of the extracts The extracts.

may be derived, for example, from lubricantdistillates or bright oils or cylinder stocks which may, for instance, range in gravity from 15.to 8 API at F. They maybe obtained from any mixed type petroleum oil such as Mid-Continent or Coastal or California crudes or, in lower yields, from Pennsylvania type oils. For use in sizing in accordance with the invention, extracts boiling above 300; C. at 760 mm. Hg pressure'are preferred, and-most preferably extracts'boiling from about C. to 300 C. at 1 mm. Hg pressure are used. Extracts obtained from narrow fractions as described in U. S. Patent No. 2,115,960 may be advantageously employed. It is often sizing judged by permeability to water of sized,

paper.

the melting point of the mixture, preferably a temperature between the melting point and about 10 C. higher is used. If-the temperatureis too low the emulsification isfunfavorably affected due to insuflicient saponification of the rosin,

' while at too high temperatures poor emulsifica- In order to obtain emulsions of the mostHde-f sirable particle size it is advantageous to melt together the rosin and cyclic extractin' the specified proportions and add the aqueousalkaline solution to the viscous mixture with suitable agitation. In this way a moderately fine, quite uniform, emulsion of the water-in-oil type is formed in which the average diameter of the particles, which are quite uniform in size, is of the order" of about-'- 10 microns or less. On further dilution of this initial emulsion with water the type of the emulsion is reversed and an extremely fine oil-inwater type emulsion isv formed with particles of less than 1' micron, usuallyof the order of10. 1 micron, average diameter, The transition point for the change in the type of emulsion generally is at about 40% to about 50% water in theemulsion. 'No important difference in results has been observed when using rosins of different origins in this process, p 1 a I A wide variety of different alkaline solutions maybe used in preparing the emulsions, Hydroxides orcarbonates of alkali metals or'am monia are particularly 'suitable; sodium ,or potassium or ammonium; hydroxides are preferred hydroxides because of their relativelylow cost; 'The corresponding, particularly the sodium and potassium, carbonates require higher temperatures and are thus somewhat less preferable. Bicarb onates may be successfully used as may alsoalkaline earth hydroxides such, for example; as calcium and magnesium hydroxides, etc. The best results have been obtaine'd with potassium'hydroxide solutions. Y I i As previously pointed out, at least 5%, and more preferably at least by weight of rosin based on the total amount of rosin and extract used should be employed, and the quantity of alkali 'should'be from about one-half to about twicethat required for saponifying the resinic acids present in the colophony, the alkali being supplied in the form of an aqueous solution of about 5% to about concentration, most preferably about 8% to'15% concentration It is advantageouswherehighly stable emulsions are desirable to use not more than the equivalent amount of alkalifor saponifying the rosin, most preferably about 90% to 100% of the equivalent amount. I

The most favorable results are obtained when the melted mixture of colophony and extract is vigorously stirred during the addition of the caustic solution. Using a cylindrical mixer having'acentral paddle rotating between fixed paddle blades, the-particle size of the emulsion was inversely proportional to the rate of stirring in the. first stage of emulsification. The rate'of stirring has little influence in the second emulsification stage, very good oil-in-w'ater type emulsion being obtained in some cases on simply pouring the initial water-in-oil paste into water. The addition of the caustic in the first stage is preferably slow and gradual. The further dilution withwater may be carried out relatively rapidly.

Itis desirable to control the temperature of the inixture of extract and rosin during the saponification stage to within a few degrees "oftion results from the coalescence of initially formed emulsion drops. A starting temperature of about 50 C. to 65 C. is satisfactory, depending upon the particular rosin and extract used. The

; temperature may be allowed to fall to about 40 C. at completion of the alkali addition and then may be reduced further by subsequent dilution. The initially'formed water-in-oil type emulsion is particularly suitable for shipment and storage, and'maybeused with or without dilution for v the gluing together of fibers of imitation leather.

For the sizing of paper or cardboard it may be added directly to the fiber pulp in the Holland beater where it is dilutedand converted to an oil-in-water type emulsion. The" diluted emulsion is also preferable'for treating textile threads and'fabrics to make them water-repellent.

The initially formed water-in-oil type of emulsions are usually 'dark' brown 'in color but dilution'to produce the oil-in-water type converts them to emulsions which are yellowish green by incident light' and reddish by transmitted light. Lighter colored sizes may-be obtained by suitable decolorization of the extract before emulsification; I

In? contrast with sizes'usually used in the manufacture of paper and cardboard which are generallymsed in the form of very dilute emulsions, e. g. of about 0.1% -to'0.5% concentration, the Iproducts of. the invention can be ,used in much more concentrated form. Thus, in the manufacture of paper and cardboard they may be employed.asi20% to 50%"emulsions of the oil-'in-water type .quite successfully, and when so used, hydrationof the pulp is promoted making possible short'er'time's in'th'e beaters, but lower concentrations can also be employed.

The new sizes of 'the invention may be used without any other change in the paper-making process. They may-be precipitated on the fiber with aluminum sulfate or thelike. AjpH of about 4.5 -to 6, depending on the type of pulp, is desirable during precipitation; -If necessary, the pH may be controlled by adding dilute acid in the beater. About 2 5 1 grams of aluminum sulfate-perkilogram of dry stuif in the beater gives satisfactory precipitation. Too much alu minum in the paper should be avoided as it adversely affects the permeability to water.

Ijh e emulsi ons of rosin andlubricating oil extractprepared according to the invention are highly stable. For instance,,no flocculation was produced in a 0.04% emulsion with a particle size of 0.12 micron on addition of hydrogen chlorideto 1/40 normal or of aluminum sulfate to 1/80 normal. The base in this emulsion had a normality of only 0.00013, so a hundred-fold excess of the acid or "aluminum sulfate did not result in'coagulation; However, in the presence of sulfite pulp a five-fold quantity. of aluminum sulfate calculated on the base present was sufficient for'complete precipitation. Although the emulsions do not readily coagulate, they occaemulsions are prepared at a pH below 9.5, preferably at aboutii to. 9, and if the initial emulsion is too alkaline it can be given" the desired pH by adding aweak acid. Addition of small amounts of protective: colloids,' such' ascasein and gums, may be used to ensure the unlimited stability of the new emulsions. 1

. Testsi with "kaolin and the like. as fillers have .6 with application-.01- thev above. emu'1s1on,.fon= a Fourdrinier machine. This paper contained 1.0% by weight: of; the colophony-Edeleanu extractresidue. mixture, calculated on dry paper subshown that the. sizes of the invention "may be show; their advantages in sizing paper of various Exemplar "'{From aKraft cellulosethree-papers-were prepared, each having a weight of -100 g. per sq. m.

. typical 7 applications of. .the sizes of the invention and stance. The sizing efiect-of this paper was excellent. the breakingstrength, stretch, folding number and water resistance meeting. allthe standard specifications. I V I li'rample III The advantages of using selected fractions of the initial lubricating oil extract are shown by the following results of comparativetests made witl'remulsions prepared as described in Examcontained 0.9% by weight/of Edeleanu extract calculated 'on dry paper substance.

A water-permeability test showed that the water had permeatedthe paper after 15 seconds.

In the manufacture of the second paper use was made of an emulsion of colophony wholly saponified with KOH. This paper contained'0'.2% by weight of colophony, calculated on dry 'paper substance; Y i" I In th water-riermeability test the water per meated the paper after 50 seconds. V

In the manufacture of thethird paper use was made of a size consisting of an emulsion prepared from a mixture of 80% by weight of the Edeleanu extract applied also for the first paper and 20% by weight ofpolophony, which mixture' was entirely saponifiedwith KOH of 10% concentration. This paper contained 1.0% by weight of th'mixture, calculated on dry paper substance.

In the water-permeability test the water-permeated the paper onlyafter 125 seconds.

1 ErampleII' Twenty parts by weight of colophonywere mixed,'while heatingwith 80 parts by weight of distillation residue of an extract prepared by treating amineral lubricating oil with sulfurous acid, To obtain' this residue the extract was distilled off to about one-half, While applyingstearn and vacuum. a j

Now to the colophony-resi'due mixture, having a ring and ball melting point of about 50 C.,'there was'addedso much of a 10% potassium hydroxide solution as to ensure the saponification of 90% of the colophony. The potassium hydroxide solution was slowlyadded to the amixture whlle ple'" II In each case bleached sulfite' pulp was sized. i V I I Using the "entire Edeleanu extract of the lu= bricating oil, it-wasfound that-2.75% byweight of size-on the' paper was required-for normal sizing,'i. e. '60 'seconds permeability to water-as measured by 'theierric thiocyanatemethod in which the paper folded into a box is floatedon ammonium 'thiocyanate solution, the inside moistened with ferric chloride solution and 'the time measured for and coloration to develop. Extraction of the Edeleanu extract with gasoline before-removal ofthe sulfur dioxide therefromgave a concentrate in 65% yield after removal'of solvents which required only 0.94% size on the paper for normal sizing. V5

The distillation residue of the same extract (the higher boiling 24%)- required only 0.63% size for normal sizing. The %-75% fraction ofthe'di-stillation required 1. 50% for normalsiz ing andgave 'avery light colored-"size.

Example IV I Incomparative tests of sizing Kraft pulp with emulsions. prepared on the'one hand from colo-' phony alone and onthe other hand froma mixe turiefof. 20 parts of .fc'olophony and-80. partsof the gasoline extract ofan Edeleanu extract of 111-. bricating oil using the. emulsification method. of

Example I'I,.the permeability of papers contain? ing 3% size was as follows: w

. example, other sizing"*mat erials such for 'in-' intensively stirring. The temperature atwhich 7 the saponification was efiectecl amounted to 60 C.

A water-in-oil emulsion was obtained which, after being cooled to 40 C., was mixed while stirring with such an amount of water of normal temperature as to produce a 40% oil-in-water emulsion.

The emulsion thus obtained, in spite of its high concentration, was still thinly liquid and had a green color with incident light. The aver- I age particle size amounted to 68 millimicrons.

A Kraft-cellulose paper was manufactured,

stanceyas are referred to in U. S. Patent No.

2,41'01357, may be'used along with the new sizes of the inVentionQAlso; other acid-acting rtecipitating agents may .be used. instead iof. aluminum sulfate for sizing according to the inven'- tion. Still other variations are possible in the invention which is not intended to be limited to the specific procedures shown by way of exam-, ple, nor by any theory proposed in explanation of theimproved results which are obtained.

I claim as my invention:

1. A- paper sizing composition consisting essentially of an aqueous emulsion having a pH of 8 a to 9 of 10 to 20,parts of colophony saponified to the extent of about to and 90 to 80 parts of an Edeleanu extract of higher boiling petroleumhydrocarbons I wherein. the .particles have anaverage sizeof less thanl micron.

2. An aqueous emulsionof the oil-in-water' typ'e suitable for sizing fibrous materials which comprises a stable dispersion in water of to 30 parts by weight of substantially'saponified colophony and 9'5 to 70 parts by weight of an extract of petroleum consisting largely of naphthenic and aromatic hydrocarbons, the water content of the mixture being at least 60% based upon the total weight of said dispersed components and wate v 3.- ,,An-emulsion oi the water-in-oiltype con sisting essentially of water and a mixture of 10 to -parts by weight of colophony, at least half of which is saponified, and 90 to 80 parts-by weightof a hydrocarbon mixture having a boiling point above"300 C. at normal pressure and consistingessentially of hydrocarbons extractable from petroleum with a solvent selectivefor aromatic hydrocarbons in the presence of paraffins. r 4,;A process of sizing Kraft, paper pulp-which comprises treating said pulp in a v Holland machine with an aqueous emulsion formed by reacting a mixture of 10 to-20 parts by;weight of cclophony and 90 to 80 parts by weightof a raf finate from the extraction with gasoline of an Edeleanu extract of petroleum hydrocarbons boiling in the lubricating oil range with a 5% to 30% aqueous solution of at least one inorganic base selected from the group consisting of the hydroxides, carbonates, and bicarbonates of the alkali metals and of ammonia, and the hydroxides of calcium and magnesium, and adding to the mixture of pulp and oil-in-water type emulsion at a pH of 4.5 to 6 not more than grams of aluminum sulfate per kilogram of dry stuff to precipitate said mixture on said fibers. I

,5. A process of sizing cellulose fibers which comprises intimately contacting an aqueous slurry of the fibers with an aqueous dispersion of a mixture of 5 to parts by weight of cold-j phonyand 95 to 70 parts of an extract of petroe leum consisting largely of naphthenic and aro-. matic hydrocarbons, which mixture has been emulsified with sufiicient of an alkali solution oi 5% to 30% concentration to saponifyat least half of said colophony, and precipitating said dispersed mixture from an emulsion of the oilin-water type onto said fibers with an acid-acting compound. l

6. A paper product comprising cellulose. fibers sized with a mixture of 10 to 20 parts of 0010- phony by weight and 90 to 80 parts by weight of a raflinate from extraction with gasoline of, an E'deleanu extract of lubricating oil.

7. Cellulose sized with a mixture of 10 to 20 parts by weight of colophony, at least half .of which has been saponified with, a potassium hydroxide solution of 8% to 15% concentration with .90 to 80 parts by weight of an extract obtained by extracting a petroleum oil'fraction boiling between 125 C. and 300 C. at 1 mm. mercury pressure with a' polar solvent; selective for aromatic hydrocarbons in thepresence of paraf- 8. Fibrous material havingon its surface a mixture of colophony and aromatic andnaphthenic hydrocarbons resulting from the precipitation with aluminumlsulfate in the presenceof said fibrous material of an emulsion formed by reacting a mixture of '5 to 30 parts of .colophony and 95 to7.0 parts by weight of an extract from extraction of a petroleum oil boiling in the lubri'e eating oil range with a polar solvent having a selective solubility foraromatic and naphthenic hydrocarbons in the'presence of parafiins with a 5% to 30% aqueous solution of an inorganic base selected from the group consisting of the hydroxides, carbonates, and bicarbonates of the alkali metals and of ammonia, and the hydroxides of calcium and magnesium, said base being present in an amount. equivalent to from= one-half to twice the requirement for saponifica'tion of,',the oolophony. l I

.9. In a process of sizing fibrous material by precipitating a sizing agent thereon, theim-v provement which comprises precipitating onto the fibers suspendedparticles of about 0.1 micron diameter from an emulsion of the oil-in 'w'ater type of 5 to 30 parts by weight of colophony,-and 95 to parts by weight of the hydrocarbon extract of high boiling'petroleum hydrocarbons, whichextract is soluble in a solvent having a preferential solubility for aromatic hydrocarbons inthe presence of paraffins, whichemulsion con; tainsat least 60% of water based upon the total weight of colophony, hydrocarbon extract and water and is formed by reacting said colophony and hydrocarbon extract with a 5% to 30% aqueous solution of an inorganicbase selected from the groupconsisting of the hydroxides, carbonates, and bicarbonates of the alkali metals and of ammonia, andthe hydroxides of calcium and magnesium; HARCO JACOB REFERENCES CITED The following references are of recordin'the file of this patent: UNITED STATES PATENTS Number Name Date 568,518 Carmichael Sept. 29, 1896 1,806,474 1 Lecocq 'May 19, 1931 1,833,038 Pratt 'Nov. 24, 1931. 1,943,975 Lathrop et al Jan. 16; 1934 2,068,299 Manson Jan. 19, 1937 2,117,256 Rafton May 10, 1938 2,285,028 Georgi et al Jan. 2, 1942 2,301,298 Light et al. Nov. 10, 1942 2,383,933 Bump Sept. 4, 1945 2,415,408 Bergier et 1. Feb. 11, 1947' OTHER REFERENcEs Chemical Abstracts, vol. 38, pages 863 and 864 (1944). x 

1. A PAPER SIZING COMPOSITION CONSISTING ESSENTIALLY OF AN AQUEOUS EMULSION HAVING A PH OF 8 TO 9 OF 10 TO 20 PARTS OF COLOPHONY SAPONIFIED TO THE EXTENT OF ABOUT 90% TO 100% AND 90 TO 80 PARTS OF AN EDELEANU EXTRACT OF HIGHER BOILING PETROLEUM HYDROCARBONS WHEREIN OF HIGHER BOILING HAVE AN AVERAE SIZE OF LESS THAN MICRON.
 6. A PAPER PRODUCT COMPRISING CELLULOSE FIBERS SIZED WITH A MIXTURE OF 10 TO 20 PARTS OF COLOPHONY BY WEIGHT AND 90 TO 80 PARTS BY WEIGHT OF A RAFFINATE FROM EXTRACTION WITH GASOLINE OF AN EDELEANU EXTRACT OF LUBRICATING OIL. 